Combination instrument.



H. M. JOHNSON. COMBINATION INSTRUMENT.

APPLIUATION FILED s1-:1 T 9, 1909.

964,785. Patented Ju1y19,1910.

H D qt RU@ mi if Y N11-1' f I 1 ""f Q .L Hilf. Jongw@ 2 SHEETS-SHEET 2.

Patented July 19, 1910.

HARRY M. JOHNSON, 0F LIVEBMOBE, CALIFORNIA.

COMBINATION INSTRUMENT.

Specification of Letters Patent. Patented July 19, 1910.

Application led September 9, 1909. Serielle. 516,904.

T o all whom| it may concern:

Be it known that I, HARRY M. JOHNSON.

-a citizen of the United States, residing at Livermore in the county of Alameda and State' of alifornia, have invented certainnew and usefulIm rovements in Combina` tion Instruments, o which the following is a s ecification. '.1

his invention relates to new and useful .improvements in combination instruments,

and more particularly to a drafting instrument, which combines the features of a T- s uare, rotractor, compass, gage, straight e ge, an iule p The principal object of my invention is to provide an instrument of the above character which is simply constructed and comprises but twoprincipal elements which may be quickly adjusted with relation to each other to produce a device which is adapt-able to any of the various uses above specified.

- Another object is to provide an instrument which is ordinarily designed to be used as a T-square, the head of which may be readily positioned at any desired angle with relation to the blade, and has integrally formed therewith va protractor whereby the desired an le may be quickly determined.

further object is to provide a device which may e quickly converted into-a compass, a movable pin point being adjustable in a longitudinal groove or slot formed in the blade, the extreme end of said blade having an opening formed therethrough for the reception of a pencil.

With. these and other objects in view, the present invention consists in the combination and arrangement of parts as will be hereinafter more fully described and particularly pointed out in the appended;

claims, it being understood that changes in the specific .structure shown and described:` may be made within the scope of the claims 1 without departing from the spirit of the invention. v i

In the drawings forming a part of this specification, and in which like numerals of referenceindicate similar parts in the several views, v

Figure 1 1s a top plan View of my 11nprovedv combination instrument. Fig. 2v is a" vertical longitudinal section therethrough. Fig. 3 is an enlarged transverse section taken on the line 3-3 of Fig. 2. Fig. 4 is a detail perspective View of the blade.' v

Referring to the drawings 5 indicates'the` constructed of hardened steel, and. 6 the head` thereof which is disposed upon one end `of the blade and in transverse relation thereto. The head 6 is in the form of a rule 7 and a protractor 8 which is integrally formed, therewith. Secured to the rule 7 there isa screw threaded bolt 9 which projects vupwardly through a central longitudinal slot 10 provided in the blade 5. The head 6 is disposed beneath the end of the blade, and the slotted centralportion of the blade is raised or elevated above the main sideportions thereof as shown at 11. The opposite'edge's of the blade 5 are scaled or graduated as shown at 12, to provide a convenientmeasurin'g device. The bolt 9y has disposed upon its threaded portion thereof a binding screw 13 which is adapted to have lfrictionall engagementxwith the surface of the raisedportion of the blade, and rigidly exterior right" hand threads which engagewith similar threadsin the bindingscrew blade of the instrument which is preferably 18. The screw;18.has a reduced depending portion .19 which 'extends through the slot 10, and receives the washerplate 20. This plate is formed with a'A central opening 21 through'which the pin point 14 passes when the shank 15. is rotated within the sleeve 17. AS the lower end of the sleeve and the binding screw are provided with right hand threads, it will be'obvious that any rotation ofthe sleeve will thus be prevented. The pinpoint will likewise be held in its adjusted position'whenv the screw 18 is adjusted u on the blader 5. An'indicator 22is carri by the screw'l 18, and is adapted to [be moved into registration with the grad- ,nations provided upon the blade.' In this manner theradius ofthe arc or clrcle to After 'the pin point has been adjusted to the desired poslt-ion upon the blade, it is -upon the'head 16.- The blade and head are then rotated, the binding screw 18 acting will thus be described u' on the paper by' the pencil 23. If desiredthe head 6 may be entirely removedfrom-,the blade when instnument'is ybeing used or'this pur- P0 .1'. s

The protractor 8` is provided with the y usual degree graduations, and the adjacent end of the blade 5 has formed thereon the pointer '24; which is l'adapted to be brought 1nto registration with any one of these graduations, when iti-s desiredto deline any par-v ticular angle upon lthe drawing surface. The inclination of beams, joist, or vstruts may also be quickly and accurately determined in a similar manner.

From the foregoing'itwill be seen that I have providedaninstrument o great utili-ty in which is combined the fea ures of a rule, protractor, compass, gage, T-square, and straight edge. 'When used asa gage the head =6 is positioned upon one edge of the work, and' the point 1.4 brought into register with the required graduation upon the blade, and the instrument moved over 'the work, thepoint 14 marking the surfaceV thereof in the usual manner. vIt will be .noted that but two principal elements are' employed,"the protractor 8 and the rule 7 being integrally formed to provide the head of the T-sqli-are. The instrument is thus vrendered very simple in construction and may be quickly converted vto providea devvice which is adaptable to the various uses above set forth. It is extremely durable in use, being formed entirely of hardened steel,

i Y tractor integrally 'ormed therewith, said protractor being provided withdegree graduations, a pointer formed upon said lade ada ted lto register with the graduations onf sal protractor, a compass oz'unt lon tudmally adjustable in the slot in said bla e, means for securing said peint in its adjusted position, scale graduations rovided upon the op ite .ed es of said b ade, a pointer carrie by sai lcom ass point adapted'to register with the gra uations upon one side of 'aid blade, and a pencil positioned in the 'outer end of said blade. as a pivot therefor, Vvand the arc or circle j 2. An instrument of the class described comprising a blade having a :centrally raised portion, 'said raised portion having a longltudinal slot formed' therein and extending substantially the entire length thereof, a cross head positioned upon one side of said blade, a screw threaded boltjcarried thereby projecting through the slot in said blade, a binding screw disposed upon said bolt ladapted to secure the cross head to the blade, a compass pin adjustably mounted in said slot, said pin having` a screw threaded shank port-ion, a nurl head formed upon the u per end. thereof, said shank having threa ed engagement in a cylindrical sleeve, a bindin screw threaded upon the exterior of said s eeve, said screw hav-ing a reduced portion extending' into said slot, a washer disposed thereon, said Washer 'having a central opening therein to receive the compass point, and a pencil carried in the outer end of said blade.

3. An instrument o' the class described comprising a graduated blade, a cross head removably disposed upon one end of said blade, a protractor integrally formed therewith, a pointer carried by the blade adapted to register with the g'raduations of said pro- 'tractor, said blade having .a longitudinally raised central portion, said raised portion having a longitudinal slot formed therein, a compass point adjustably mounted in said slot, said point having a left hand threaded shank portion, a'sleeve provided with interior and exterior left and right hand threads respectively, said threaded shank being engagedwith the interior threads of said sleeve, a binding screw engaged with the exterior threads on said 'sleeve and extending through the slot in said blade, a securing plateengaged upon the end of said bindlng screw, a pointer carried by said screw adapted to register with the graduation's on said blade, .said blade. having an opening oentrall formed through the outer end of said bla e, and a pencil positioned in said opening.

In testimony whereof I aflix my signature, in presence ot two witnesses.

HARRY M. JOHNSONl Witnesses:

` HANS JOHNSON, CARL F. Woon, 

